yeah waiting an hour for a build is unacceptable, I’m modifying this build script to run locally
These people took the floppy controller used in the BBC Micro, an Intel 8271, and set about finding out how it worked. In the course of that, they discovered it's actually a dual core processor, with over 3x the transistor count of a 6502.
Then they dumped the ROM by visual inspection of the micrographs of a decapped 8271, and reverse engineered the instruction set, with a full disassembly available.
h a r d c o r e